const child =  require('child_process')
const spawn = child.spawn;
const ls = spawn('ls', ['-lh', '/usr']);

ls.stdout.on('data', (data) => {
    console.log(`stdout: ${data}`);
});

ls.stderr.on('data', (data) => {
    console.log(`stderr: ${data}`);
});

ls.on('close', (code) => {
    console.log(`child process exited with code ${code}`);
});

const sh = child.exec('ls -lh /usr', (error, stdout, stderr) => {
        if (error) {
    console.error(`exec error: ${error}`);
    return;
}
console.log(`stdout: ${stdout}`);
console.log(`stderr: ${stderr}`);
});